Transdermal oestrogen	Micronised progesterone
More reliable absorption than oral oestrogen	Oral preparation given with oestrogen as part of HRT, either cyclically or continuously
Less likely than oral oestrogen to cause side effects such as nausea	Neutral effect on blood pressure
Does not increase VTE risk even in women who are at high risk, such as those with prothrombotic mutations (including factor V Leiden)	Not associated with VTE risk unlike other progestogens
Should be first line in women with obesity, diabetes, or liver disease	Neutral effect on CVD risk unlike other progestogens
Oral oestrogen can lower libido by increasing SHBG levels whereas transdermal oestrogen does not have this effect	Less likely to cause side effects such as fluid retention
Does not have an increased stroke risk	Lower risk of breast cancer compared with progestogens
Costs around £4–£5 a month	Costs around £4 a month

CVD = cardiovascular disease. HRT = hormone replacement therapy. SHBG = sex hormone binding globulin VTE = venous thromboembolism.